X-ray imaging systems may be used for various clinical procedures ranging from catheter or needle based interventions in radiology, cardiology, or oncology up to surgical procedures. For example, trans-catheter aortic valve implementation (TAVI) is a very important procedure, where a minimal invasive surgical intervention is carried out. Accordingly, a surgical entrance point and its spatial relation to the underlying anatomy of the patient, which is also referred to as the subject in the following description, is important for safe and accurate interventions. Projecting the subject's anatomy on the body surface is a technique to guide an interventional device to be inserted.
U.S. Pat. No. 6,314,311 B1 relates to a registration system for use in connection with an image guiding surgery system. It includes a medical diagnostic imaging apparatus for collecting image data from the subject. An image data processor reconstructs an image representation of the subject from the image data. An image projector depicts the image representation on the subject. However, the images of the subject are obtained prior to a planned interventional and/or surgical procedure via the medical diagnostic imaging apparatus. The images are taken at different positions and time of a respiratory cycle of the subject. The depicted image projected on the subject is then selected accordingly from the set of diagnostic images in order to bring the image in coincidence with the anatomy of the subject.
International Patent Application Publication No. WO2013/055707 A1 relates to an image-guided surgery system, which allows a surgeon to have more information available at the surgical site by performing procedure. For this purpose, a camera/projection combination unit is provided in conjunction with a medical imaging device such as MRI or CT. A multi-modality image registration system supporting an interactive overlay of potentially fused pre- and intra-operative image data is disclosed, which could support needle-based interventions.
U.S. Pat. No. 6,314,311 B1 relates to an image guidance surgery system with a registration system, which is employed to correlate an image of the subject's anatomy with the corresponding actual anatomy of the subject present within a subject support system defined in real space. For this purpose, a detection unit resolves the spatial location of emitters affixed to the patient support, such that the location of the subject thereon is tracked. Further, a rotation, translation and scaling processor of the system determines appropriate corrections to be applied to the image for the respective location of the subject and generates adjustment employed by a projector processor, such that the image being projected is depicted in a proper size and rotation on the region of interest of the subject.
U.S. Patent Application Publication No. US-2014/0350389 A1 relates to a system and a method for surgical planning and navigation. For this purpose, data representing an image of a portion of a patient's body is received. A first three-dimensional model of the portion of the patient's body is generated based on the data representing the image. A second three-dimensional model of a medical device is fitted within the first three-dimensional model at a location in proximity to the target region to create a combined three-dimensional model. Further, a two-dimensional projection of the combined three-dimensional model is created. Furthermore, the two-dimensional projection is matched to a real-time two-dimensional intraoperative image. The two-dimensional projection and the real-time two-dimensional intraoperative image can both be displaced to facilitate comparison.